1. Field of the Invention
This invention relates to a vehicle transfer system for use in a vehicle assembly line.
2. Description of the Prior Art
There has been known a vehicle transfer system for use in a vehicle assembly line comprising a first conveyor (a single slat conveyor) which transfers a vehicle while supporting the vehicle on its chassis with the tires being floated, a second conveyor (a double slat conveyor) which transfers the vehicle body while supporting the vehicle on its tires, and a ride-over table disposed between the first and second conveyors which the tires of the vehicle are caused to ride over so that the chassis is lifted away from the vehicle supporting table of the first conveyor. When the front tires of the vehicle transferred by the first conveyor reach the ride-over table, they ride over an ascending slope formed on the receiving side of the ride-over table and roll up on the slope. Thereby, the front portion of the chassis is lifted above the vehicle supporting table of the first conveyor. Thereafter, the front tires roll on a substantially horizontal top surface of the ride-over table and by the time the front tires approach the delivery side of the ride-over table, the rear tires have rolled up on the ascending slope to the substantially horizontal top surface. When the vehicle further advances, the front tires roll down a descending slope formed on the delivery side of the ride-over table into the receiving side of the second conveyor, and thereafter the rear tires roll down the descending slope into the receiving side of the second conveyor.
Thus, in the conventional vehicle transfer system, the vehicle is transferred to the second conveyor from the ride-over table by causing the vehicle to run on the descending slope and accordingly the vehicle runs on the second conveyor by inertia. Therefore, when the vehicles are transferred to the second conveyor, the transfer intervals at which the vehicles are transferred and which has been fixed on the first conveyor fluctuate, adversely affecting various operations to be carried out along the second conveyor.
Therefore, conventionally, an operator must ride on each vehicle before the vehicle reaches the ride-over table and brake the vehicle to adjust the transfer intervals after the vehicle runs into the second conveyor. However, there have been problems that it is impossible for the operator to precisely adjust the transfer intervals and at the same time, a plurality of operators are required exclusively for this purpose.
Further in the conventional vehicle transfer systems, there has been a problem that the vehicle is apt to be displaced in the direction perpendicular to the transfer direction if the front tires are turned right or left when the front tires ride over the ascending slope of the ride-over table or when the vehicle rolls down the descending slope of the same to the second conveyor.